System for the application of samples on a substrate

ABSTRACT

Novel apparatuses and methods for depositing or placing substances on substrates or plates are described. The invention relates to automated and semiautomated apparatuses and methods for controlled volume and precise placement of substances on substrates. Combinations of applicator tips, applicator tip assemblies, applicator reservoirs, applicator holders and movable racks precisely and accurately place samples and testing chemicals on substrates. Applicator tips particularly useful for dunk transfer and deposit processes and for carrying substances are disclosed. Apparatuses for precisely moving applicator holders, applicator reservoirs and tips are disclosed. The methods and apparatuses also have features for pre-loading substances on applicators and applicator reservoirs and precisely delivering the preloaded substances to substrates.

RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.60/016,933, filed May 6, 1996, which is hereby incorporated byreference.

TECHNICAL FIELD

This invention is in the medical and chemical related field. Theinvention relates to the placing of samples on a substrate.

BACKGROUND

Scientists and medical technicians are constantly searching for betterways to place, transfer and/or apply samples on various substrates fortesting or diagnostic-type purposes. The placement, volume, anddimensions of such samples on a substrate are important to the resultsof the procedures carried out on the samples. In some instances,improper application of the samples on a substrate will significantlyalter or destroy the test results. One such procedure, which is subjectto poor results based upon the application of samples, is the procedureof zone electrophoresis. For further background on electrophoresis see,for example, U.S. Pat. No. 5,137,614, issued to Golias on Aug. 11, 1992,entitled “IMMUNOFIXATION ELECTROPHORESIS CONTROL SYSTEM” andincorporated herein by reference.

For further background on the application of biological samples for anelectrophoresis process, see U.S. Pat. No. 5,405,516, issued to Bellonon Apr. 11, 1995, entitled APPARATUS FOR THE APPLICATION OF BIOLOGICALSAMPLES TO AN ELECTROPHORETIC SLAB SUPPORT, herein incorporated byreference.

Present methods for the automatic application of samples, especiallyfine samples, to a substrate or flat surface are inadequate.

It is an object of the invention improve upon the methods and devicesfor depositing samples or fluids on a substrate.

It is an object of the invention to control the amount of fluid appliedto a substrate.

It is an object of the invention to control the footprint or shape ofthe fluid applied to a substrate.

It is an object of the present invention to strive to produce a nearlytwo dimensional deposit of fluid onto a substrate.

It is an object of the present invention to provide a semi-automatic andautomatic method and device for placing fluid on a substrate.

It is an object of the present invention to reduce the risks of damagingthe applicator or the substrate during a deposit or delivery.

SUMMARY OF THE INVENTION

The novel methods and apparatuses for depositing or placing substanceson substrates disclosed include applicator tips, applicator reservoirs,applicator tip assemblies, automated and semiautomated apparatuses andprocesses for using applicators. The methods and other apparatuses areused to automatically or semiautomatically place controlled amounts ofsubstances on substrates. Combinations of applicator tips, applicatortip assemblies, applicator reservoirs, applicator holders and movableracks precisely and accurately place samples and testing chemicals onsubstrates. Racks and other equipment are used to bring the applicatorsor transferred substances into contact with the substrates. Preferablyracks with vertical movement are used to precisely deposit samples andfluids.

Specifically, methods and hardware for applicator tips which carry anddeposit sample fluid using lyophilic surfaces are disclosed. Generally,the tips are formed in two parts, one part carries sample fluid and thesecond part does not. Barriers and other techniques are used to preventthe second part of the tips from carrying fluid. The tips are mounted onapplicator holders which are placed on racks and used in automatic andsemiautomatic processes.

Applicator reservoirs can be used to pre-load substances or fluids forlater transfer to substrates. The reservoirs deposit or place controlledvolumes of substances or fluids on substrates or plates. The preferredmethod mixes fluids with polymers to form a gel which is cast in areservoir. The gel is then placed in contact with a substrate to depositthe fluid. Preferably, these reservoirs are connected to applicatorholders which are used in combination with racks and other deliveryapparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of the fluid applicator.

FIG. 2 is a front view of a multiple applicator tip assembly.

FIG. 3 is an enlarged view of an applicator tip.

FIGS. 4-11 are enlarged views of different applicator tipconfigurations.

FIG. 12 is a perspective view of an applicator holder with a guard.

FIG. 13 is a top view of a single channel supply tray.

FIG. 14 is a perspective view of an alternative supply tray.

FIG. 15 is a perspective view of a substrate or gel plate.

FIG. 16 is a side view of the base and the applicator guide within theapplication station.

FIG. 17 is a perspective view of the applicator guide.

FIG. 18 is a perspective view of the applicator rack.

FIG. 19 is a perspective view of a chemical delivery system applicator.

FIG. 20 is a top view of an automated immuno-fixation electrophoresissystem.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

I. Introduction

The present invention is a method and apparatus for supportingimmuno-fixation electrophoresis or any other type of testing whichrequires precise and accurate sampling. Generally, the system comprisesan application station with a fluid applicator, a chemical deliverysystem or station with a chemical delivery applicator and a substrate.

Generally, the fluid applicator retains a fluid sample for deposit ontoa substrate. The application station is a semiautomatic or automaticdevice for insuring precise deposit of the fluid sample on a substrate.The chemical delivery system applies chemicals or substances to asubstrate, and the substrate is the medium for facilitating successfultest results.

II. Major Subsystems

A. Fluid Applicator

FIG. 1 shows a front view of a fluid applicator 106. The fluidapplicator 106 comprises an applicator holder 118 and a multipleapplicator tip assembly 122 with applicator tips 130. The applicatortips 130 extend beyond the bottom of the applicator holder 118.

The applicator holder 118 is made of a sturdy material, preferablyplastic. Typically, the plastic is styrene. The body of the applicatorholder 118 includes a right guide 170, left guide 174, and three pins126. The two guides 170, 174 are used to align the applicator holder 118within an application station for automatic or semi-automaticapplication. In the preferred embodiment, one of the guides is widerthan other guide to insure the applicator holder 118 is properlyinserted into an application station. In alternative embodiments, anydifference in the two guides' shape or size can accomplish the sameresult. If the applicator tip 130 configuration is symmetrical aroundthe central axis 116, the guides 170, 174 may be identical.

The three pins or snaps 126 on the applicator holder 118 are used toattach the multi-applicator tip assembly 122 to the applicator holder118. The three pins 126 protrude from the applicator holder 118. Thepins 126 may be circular, square, elliptical, or any other shape. Thenumber and position of the pins 126 may vary. In a preferred embodiment,the pin heads are larger than their base. Thus, the multiple applicatortip assembly 122 is attached by aligning holes in the assembly 122 witheach pin, and snapping the assembly 122 onto the applicator holder 118.

In alternative embodiments, there are a variety of ways to firmly attachthe applicator holder 118 and the multiple applicator tip assembly 122.For example, they could be attached using double sided tape, heat orultrasonic sealing, or any common type of adhesive, such as glue. Inthese embodiments, the holder preferably has a slot or groove to insurethe applicator tips 130 are properly positioned.

FIG. 2 shows the multiple applicator tip assembly 122. In the preferredembodiment, the multiple applicator tip assembly 122 is approximately 4½inches long, 1 inch high, and the width of a piece of paper. The widthof the assembly is important because, ideally, immuno-fixationelectrophoresis desires a two dimensional line of biological fluidplaced on the substrate. The two dimensional line should have a lengthdirection perpendicular to the direction of electrophoretic movement, adepth dimension into the substrate at right angle to the direction ofelectrophoretic movement, and the smallest possible width dimension.These dimensions directly affect the accuracy of the test results.

FIG. 3 shows a single applicator tip 130. The applicator tip 130comprises a first portion 140, second portion 144, and a blade 147. Thesecond portion 144 is designed to retain fluid. The first portion 140 isdesigned to create a barrier 150 which limits the amount of fluiddeposited by the applicator tip 130. The barrier 150 may also be createdby the physical or chemical characteristics of the second portion 144.In alternative embodiments, the barrier 150 limits the amount of fluidretained.

In the preferred embodiment, the applicator tip 130 retains fluid fromthe barrier 150 to the blade 147. This distance is usually within therange of 0.05 through 0.50 mm. In the preferred embodiment this distanceis approximately 0.18 mm. The distance is small because, the smaller theamount of fluid retained by the applicator tip 130, the easier it is forthe fluid applicator 106 to precisely deposit the fluid on thesubstrate. The barrier 150 can take a variety of forms, such asphysical, chemical, electrical, or any combination of these techniques.

Some of the common physical barriers 150 are apertures, holes,perforations 148, or changes in the texture of the surface. These holes148 may be circular, elliptical, or any other shape. In the preferredembodiment six holes or perforations 148 are placed approximately at0.018 inches above the blade 180 on the applicator tip 130. The holes148 are preferably approximately 0.006 inches in height and oval inshape. The holes 148 are horizontally aligned near the bottom of theapplicator tip 130. The holes 148 create a physical barrier 150 to thefluid which prevents the applicator tip 130 from retaining fluid abovethe holes 148. This applicator configuration prevents too much fluidfrom being retained at the ends of the applicator tip 130 and allows theapplicator tip 130 to bend in the vertical and horizontal planes.

FIGS. 4-10 show a variety of different applicator tip 130configurations. FIG. 4 shows an applicator tip 130 with a physicalbarrier 150 (i.e. the horizontal opening) just above the blade 147. FIG.5 shows an applicator tip 130 with serrated teeth. FIG. 6 shows anapplicator tip 130 with a physical barrier 150 created by a horizontalrow of closely spaced circular openings. FIG. 7 shows an applicator tip130 with “key hole shape” openings evenly spaced along the bottom of thetip 130. The “key hole shape” openings are tallest in the middle andbecome progressively smaller toward the ends. FIG. 8 shows an applicatortip 130 with three horizontal openings just above the bottom. FIG. 9shows an applicator tip 130 with a row of circular openings just abovethe bottom of the tip 130. The circular openings are largest at themiddle and become progressively smaller toward the ends. FIG. 10 showsan applicator tip 130 with a “mouse hole” shaped opening. Any of theseapplicator tips 130 may be disposable.

A physical barrier 150 may also be created by making the first portion140 of the applicator tip 130 rough or texturized. Rough or texturizedsurfaces have lyophobic characteristics. Thus, if the first portion 140of the applicator tip 130 has a rough surface, the rough surfaceprevents the applicator tip 130 from retaining the fluid sample abovethe barrier 150.

Some common chemical or electrical barriers 150 are created by using anapplicator tip 130 with specific lyophobic or lyophilic characteristicsor chemically treating the surface. For example, if the first portion140 of an application tip 130 is made of a lyophobic substance and thesecond portion 144 is made of a lyophilic substance, only the secondportion 144 of the applicator tip 130 will retain fluid. To achievethese results, the first portion 140 should have lyophobiccharacteristics sufficient to generally prevent it from retaining thefluid sample, and the second portion 144 should have lyophiliccharacteristics sufficient to generally retain the fluid sample. Theseresults can also be obtained by coating the surface of the applicatortip 130 with chemicals which causes the first portion 140 to posses thenecessary lyophobic characteristics and the second portion 144 topossess the necessary lyophilic characteristics.

FIG. 11 shows an applicator tip 130 suitable for a chemical orelectrical barrier. Some of the techniques for altering the lyophobic orlyophilic characteristics of a portion of the applicator tip 130 are:electrically (corona discharge), chemically (hydrophilic polymer-naturalor synthetic) and/or, as stated above, mechanically (abrading orperforating the surface).

The preferred technique for creating a chemical barrier 150 is to makethe applicator tip 130 out of polyester or nylon, which passes thenecessary lyophobic characteristics for the first portion 140, andcreate the second portion 144 of the applicator tip 130 by metalizingthe polyester surface.

The end of the applicator tip 130 is called the blade 147, as shown inFIG. 3. The blade 147 is generally a smooth flat edge. In the preferredembodiment, the blade 147 possesses the same lyophilic characteristicsas the second portion 144 of the applicator tip 130 so that the fluidsample adheres uniformly to the blade 147 and second portion 144.

In one embodiment, the blade 147 is that portion of the applicator tip130 which contacts the substrate or plate 110, and thus, initiates thedeposit of the retained fluid onto the substrate. In this embodiment,the retained fluid is released onto the substrate because the contactbetween the blade 147 and the substrate breaks the surface tension ofthe retained fluid. In this embodiment, the blade 147 should contact thesubstrate in a manner to prevent puncturing or damaging the substrate.

In an alternative embodiment, the blade 147 may never contact thesubstrate. For example, the retained fluid may be released when theretained fluid attached to blade 147 contacts the substrate.

In addition to the multiple types of applicator tip 130 configurations,there are many different ways to use the applicator tips 130,individually or in combination. For example, some applicator holders 118may use a single applicator tip 130, while others may use a plurality ofapplicator tips 130. The single applicator tips 130 may also be combinedto resemble a multiple applicator tip assembly 122. In the preferredembodiment, many applicator tips 130 are permanently connected to form amultiple applicator tip assembly 122.

Moreover, multiple fluid applicators 106 can also be combined to form acartridge (not shown). Cartridges may be used to connect applicatorholders 118 for loading into the applicator rack 540. Preferably thecartridges are made of plastic and hold three or more applicatorholders. Use of the cartridges makes the loading and unloading of theapplicators in the rack a quick and simple task.

FIG. 12 shows an applicator holder 118 with a guard 162 to protect theapplicator tips 130 from damage during manufacture, transport,packaging, etc. The applicator guard 162 is removed or snapped off fromthe applicator holder 118 at a break point 166 at either end of theapplicator holder 118. The multiple applicator tip assembly 122 is notshown in FIG. 12.

The fluid applicator 106 acquires the fluid sample from a supply tray.As shown in FIG. 13, a supply tray 102 may have a single channel 114 forholding fluid. The channel 114 may be any length. For example, if thechannel 114 is built to service a fluid applicator 106 with a singleapplicator tip 130 the channel will be short. If the supply tray 102 orchannel 114 is built to service a multiple applicator tip assembly 122,the channel 114 will be long enough to accommodate the insertion of allthe applicator tips 130 simultaneously. A supply tray 102 is generallymade out of plastic or metal. When used for immuno-fixationelectrophoresis, the sample stored in the supply tray 102 is usually abiological fluid, such as blood.

FIG. 14 shows a preferred supply tray 104. In this embodiment, thesupply tray 104 has three rows 151 of evenly spaced receptacles 155. Thesize and spacing of the receptacles 155 depends on the size and spacingof the multiple applicator tip assembly 122. Preferably, the receptacles155 are large enough to accommodate one or more applicator tips 130 anddeep enough to insert the entire second portion 144 of the applicatortip 130. The supply tray 104 with rows 151 of individual receptacles 155is preferred because each row and receptacle 155 may be filled with adifferent sample fluid. Thus, supply tray 104 is capable of testing morefluids simultaneously than supply tray 102. For example, the preferredsupply tray 104 may contain three rows 151 and each row 151 may includeeighteen receptacles 155. Eighteen receptacles 155 in each row 151allows each row to contain fluid samples from three different patients.Each patient is allotted six receptacles 155 to allow each patient'sblood to be tested with six different chemicals (for example serum andantisera).

FIG. 15 shows a substrate or gel plate 110. In the preferred embodiment,the gel plate 110 is made out of agarose gel. The substrate 110 shouldbe large enough to receive the fluid samples and be subjected toelectrophoresis. For examples of gel plates see U.S. Pat. No. 4,892,639,issued Jan. 9, 1990, entitled “ELECTROPHORESIS PLATE AND METHOD OFMAKING THE SAME”; U.S. Pat. No. 4,975,173, issued Dec. 4, 1990, entitled“ELECTROPHORESIS PLATE AND MAKING OF THE SAME”; and U.S. Pat. No.5,045,164, issued Sep. 3, 1991; entitled “ELECTROPHORESIS PLATE FORDIVERTING GENERATED FLUID”, all of which are herein incorporated byreference.

In operation, the fluid applicator 106 is moved to a position above thesupply tray 102, 104 with the application tips aligned above the channel114. The applicator tips 130 are then inserted, dunked, or dipped intothe receptacles by movement of the applicator holder 118. During the“dunking” process, the applicator tips 130 retain a quantity of thefluid sample from the channel 114 or receptacle 155. (The fluid sampleis not shown in FIG. 12 or 13). Following the “dunking” procedure, theapplicator 106 is removed from the channel 114 or receptacle 155 by theapplicator holder 118, moved towards the substrate 110 and lowered inthe vertical direction onto the substrate 110 to release the retainedfluid.

B. Application Station

As stated above, an application station is a semiautomatic or automaticdevice for insuring precise deposit of the fluid sample on the substrate110. The application station comprises three main components: a base,applicator guide, and applicator rack.

FIG. 16 shows a side view of the base 502 and applicator guide 510portions of the application station. The base 502 is flat solidstructure which can be made of metal, hard plastic, wood, or any sturdymaterial. The base 502 is usually rectangular with four columns orpillars 506, but could take almost any shape or contain any number ofpillars 506. In the preferred embodiment, the base is approximately fiveto seven inches wide, a half inch to two inches high, and five to seveninches long. The pillars 506 protruding from the base 502 connect thebase 502 to the applicator guide 510 by fitting within the applicatorguide's feet 514. The applicator guide's feet 514 are usually femaleends designed to accept the pillars 506. The base 502 and applicator 510are shown as two separable components, but these components could beconstructed in a variety of different configurations. In other words,the base 502 and applicator guide 510 may be a single unit.

FIG. 16 also shows a substrate or gel plate 515 in between the base 502and applicator guide 510. The substrate 515 is a flat plateapproximately the same size as the base 502 with four holescorresponding to the four pillars 506 protruding from the base 502. Thepillars 506 pass through the substrate 515 to hold the substrate 515 inplace during application. In an alternative embodiment, the substrate515 may be smaller than the base 502 and fit inside an indentation inthe base 502.

FIG. 17 shows a top view of the applicator guide 510. The applicatorguide 510 is designed to control the application of biological fluidsand other chemicals onto the substrate 515. The applicator guide 510controls these applications with the two tracks 524, 528 positioned inparallel. The tracks 524, 528 are used to control the speed and locationin which the fluids, chemicals or substances are deposited onto thesubstrate 515. The tracks 524, 528 control the location in which a fluidis deposited because they are designed to hold the applicator rack in afirst position and a second position. In the first position, the tracks524, 528 hold a fluid applicator 106, usually mounted in an applicatorrack, above the substrate. In the second position, the tracks 524, 528hold the fluid dispenser in a position closer to the substrate. Theposition closer to the substrate is designed to hold the fluidapplicator 106 in a position which will cause the surface tension of theretained fluid to break. Thus, the fluid is released and deposited onthe substrate.

In the preferred embodiment, the tracks 524, 528 control the movement ofthe fluid applicator 106 with three slides 530, 531, 532. The righttrack 524 has two slides 530, 531, one located near each end, and theleft track 528 only has one slide 532 in the middle of the track 528. Inalternative embodiments, the two tracks 524, 528 can have the samenumber of slides in the same location or a variety of otherconfiguration. As stated above, the feet 514 are used to connect theapplicator guide 510 to the base 502.

FIG. 18 shows an applicator rack 540 for use with the applicator guide510. The rack applicator 540 has a right front post 544, a right rearpost 548, and a left post 552. The applicator rack 540 may be attachedto the applicator guide 510. The right front post 544 is designed toalign with the applicator guide's right front slide 530. The right rearpost 548 is designed to align with the applicator guide's right rearslide 531, and the left post 552 is designed to align with theapplicator guide's left slide 532. In the preferred embodiment, eachpost is aligned with its corresponding slide, and slowly lowered in thevertical direction. The sliding or lowering of the applicator rack 540from top of the slide to the bottom causes the applicator 106 andapplicator tip 130 to move from a position above the substrate 515 to aposition in contact with the substrate 515. When the applicator tip 130contacts the substrate 515, it breaks the surface tension between thefluid and the applicator tip 130. When the surface tension is broken,the fluid carried on the applicator tip 130 is deposited on thesubstrate 515. The applicator tip 130 does not necessarily have tocontact the substrate 515 to break the surface tension. The applicatorguide 510 and applicator rack 540 are designed to minimize the contactand prevent any damage to the substrate 515.

The slides 530, 531, 532 are also used to improve the control over thespeed in which the applicator rack 540 is lowered onto the substrate515. The slides 530, 531, 532 improve the control because they createfriction. The friction slows the dissent of the applicator rack 540. Inan alternative embodiment, slides 530, 531, 532 are not required. Theapplicator rack 540 may simply be lowered in the vertical direction. Inanother alternative embodiment, the applicator rack 540 may contact thesubstrate by moving in a circular path.

The applicator rack 540 also has a first set of slots 556 and a secondset of slots 560 for holding applicators. Each set of slots contacts aplurality of individual pairs of slots. The slots 556, 560 are designedto hold guides 170, 174, like the ones shown in FIG. 1. These slots 556,560 may differ in size or shape to insure the applicator 106 is properlyinserted. In the embodiment shown, the first set of slots 556 is able tohold six applicators 106 simultaneously because it has six individualslots. However, the preferred operation of the system is to leave anempty slot between each applicator 106, limiting the number ofapplicators 106 inserted simultaneously to three.

The second set of slots 560 includes twelve individual slots. Theseslots are used to hold chemical dispensers, sera dispensers or otherapplicators containing chemicals (some of which may improve thevisibility of the results achieved from immuno-fixationelectrophoresis).

In the embodiment shown in FIG. 18, the first set of slots 556 ispositioned perpendicular to the second set of slots 560. Thisconfiguration is designed to facilitate use of the application stationfor different types of electrophoresis, including immuno-fixationelectrophoresis. Specifically, the first set of slots 556 are designedto deposit the biological fluid in a “two dimension” line in the Xdirection. The two dimensional line is achieved by inserting anapplicator 106 into the first set of slots 556, aligning the applicatorrack 540 with the slides 530, 531, 532 in the applicator guide 510;lowering the applicator rack 540 along these slides; and depositing thefluid retained on the applicator tip 130 onto the substrate 515. Thedeposit is approximately a two dimensional line because of the shape ofthe tip.

Once the fluid is deposited on the substrate 515, electrophoresis isperformed. Electrophoresis causes the molecules deposited in the twodimensional line to migrate in a direction perpendicular (i.e., Ydirection) to the two dimensional line created by the deposited fluid.

After the electrophoresis is completed, a second applicator 106 isloaded in the second set of slots 560. Then the second applicator 106 islowered to dispense chemicals in the Y direction, perpendicular to theoriginally deposited fluid. Since as a result of the electrophoresis,the molecules migrated in the Y direction, the chemicals are dispensedperpendicularly to the original deposit in the X direction.

Also, in the embodiment shown in FIG. 18, the first set of slots 556 andthe second set of slots 560 are both aligned in the XY plane. Thus, theapplicator rack 540 should not be loaded with applicators 106 in thefirst set of slots 556 and applicators 106 in the second set of slots560 at the same time. One of the advantages of this configuration isthat it decreases the size of the application station. However, inalternative embodiments, applicators and dispensers can be loaded in thefirst set of slots and the second set of slots simultaneously.

In an alternative embodiment, two sets of slots can be usedsimultaneously. The first set of slots 556 and a second set of slots 560are positioned far enough apart along the line of movement of the rack(along the tracks), that the two sets of slots 556, 560 do not interferewith each other during use. In this manner, two sets of applicators canbe loaded, one in each set of slots, and remain loaded during an entireprocedure. The slides are configured in such a manner that the rackwould travel along the slides, deposit fluids from the first set ofapplicators and then be moved so that the fluids on the second set ofapplicators could be lowered vertically and placed on the substrate(without interference from the first set of applicators). Preferably,the rack for this embodiment is larger in the direction of movement andthe slides to support such a larger rack are longer than the rack 540used in the preferred embodiment.

Some of the steps for using the application station or fluid applicator106 may include: placing the substrate or gel plate 515 into theapplication station; connecting the application guide 510 to the base502; inserting a first applicator 106 into the applicator rack 540,usually in the first set of slots 556; aligning the pillars 506 of theapplicator rack 540 including the first applicator with the applicatorguide 510; lowering the applicator rack 540, including the firstapplicator 106, onto the substrate 515; raising the applicator rack 540,including the first applicator 106 away from the substrate 515; removingthe first applicator 106 from the applicator rack 540; removing thesubstrate 515; performing electrophoresis on the fluid deposited on thesubstrate 515; reinserting the substrate 515 into the applicationstation; installing a second applicator or dispenser 106 into theapplicator rack 540, usually in the second set of slots 560; realigningthe applicator rack 540 with the applicator guide 510; applying thesecond applicator 106 using the applicator rack 540 onto the results ofthe electrophoresis; raising the second applicator 106 using theapplicator rack 540; removing the substrate 515 treated with thechemical or substance from the second applicator 106; and viewing theresults. Electrophoresis may also be performed on the substrate whilethe substrate is on the base beneath the racks.

C. Chemical Delivery System

In many chemical delivery systems for delivering chemicals or substancesto test samples, there are problems associated with the volume ofchemicals delivered and the control of the delivery. Specifically, thereare problems delivering a known quantity of the chemicals to a preciselocation on a substrate or sample located on a substrate. Many times,the test sample lanes on the substrate are small, in the range of 1 mmto 5 mm wide. Also, because of factors such as fluid viscosity andadhesion coefficients, the volume of the chemical being delivered mayprematurely or spontaneously unload and drip prior to delivery. Deliveryapplicators in the prior art have these and related problems.

FIG. 19 shows a delivery system applicator 600. The delivery systemapplicator 600 includes a delivery system applicator holder 604 with aleft guide 608, a right guide 612, and a reservoir 616.

The delivery system holder 604 may be constructed similar to the samplefluid applicator holder 118. The delivery system applicator holder 604can be constructed of a plastic, such as styrene, or other materialsknown in the art. The right and left guides 608, 612 may be madeidentical and symmetrical or, may be shaped differently so that theholder 604 can only be aligned or placed in the applicator rack 540 inone direction or position. The left and right guides 608, 6122 may beconstructed similar to the guides in the sample fluid applicator 106described above.

The reservoir 616 is preferably an elongated well or tunnel-shapedreservoir. The reservoir 616 has an opening preferably located at thebottom and away from the delivery applicator holder 604. The reservoir616 may be made from a variety of materials including those from whichthe applicator holders 604, 118, are constructed. The reservoir 616 isconnected to the holder 604. A variety of methods may be used forconnecting the reservoir to the holder, including a snap fit plasticconnection, adhesives (such as glue or tape), screws or fasteners, heatweld, ultrasonic sealing, etc. Many of the methods described above forconnecting the multiple applicator tip assembly 122 to the applicatorholder 118 can also be used to connect the reservoir 616 to the deliverysystem holder 604.

Preferably, the reservoir 616 is shaped or formed to hold a gel or“gel-like” substance. Various configurations are possible for thereservoir, including with lips or ledges around the edge of thereservoir and other structures within the reservoir 616 to assist inkeeping the gel held within the reservoir 616.

A variety of fluid retaining substances (such as gel forming substances)may be used in the reservoir 616 of the delivery system 600. Someexamples are polymers, gels, agarose, polysaccharide, carrageenan, andother fluid retaining substances that have the consistency necessary tobe effectively used in the reservoir 616.

A variety of chemicals or fluids may be delivered using the discloseddelivery system 600. For example, serum protein and antiserums may bedelivered using the delivery system 600. The serum proteins andantiserums are held by the fluid retaining substances in the reservoir616.

In operation, it is preferred that a mixture of the chemical or fluid tobe delivered and the fluid retaining substance is made and poured, castor placed in the reservoir 616 where it congeals and is held or adheredto the reservoir 616. Although various methods for the reservoir 616 tohold the fluid retaining substance and chemical or fluid are possible,it is preferred that the chemical and fluid retaining substance are cast(together) into the reservoir 616 where the cast itself holds the fluidretaining substance and chemical in place. Other methods may be used forholding the fluid retaining substance and chemical in the reservoir 616:including shaping the reservoir 616 so as to hold the fluid retainingsubstance (and chemical) such as with lips or ledges running along theperimeter of the reservoir 616, adhesives, or other methods. Generally,the delivery system 600 is loaded with fluid retaining substance andfluid or chemical when it is in an inverted or upside down position.Loading the fluid retaining substance and fluid in this manner allows itto gel in place within the reservoir before the forces of gravity beginto pull on it and pull it away from the reservoir 616. This pre-loadingof the chemical or fluid eliminates the need for a dunking step.

In use, the applicator 600 is preferably held in an upright position bysemiautomatic or automatic chemical delivering device. Such a device,several of which are herein disclosed, would use the guides 608, 612 tohold the delivery system applicator 600 in place during the deliveryprocess. The device brings the delivery system applicator 600 towardsthe substrate 110, 515 and creates a contact between the substrate andthe delivered chemical and/or fluid retaining substance in the reservoir616. When the “gel-like” substance in the reservoir makes contact withthe substrate, a controlled volume of chemical or fluid is delivered tothe substrate. Using this delivery method the delivered chemical orfluid can also be placed in a precise location on the substrate.

With regard to using the following apparatuses and methods in anautomated immuno-fixation electrophoresis process using six chemicalsample treatments, the following information applies. For generalinformation on the automated immuno-fixation electrophoresis process,see U.S. Pat. No. 5,137,614 entitled “IMMUNOFIXATION ELECTROPHORESISCONTROL SYSTEM”, issued on Aug. 11, 1992, hereby incorporated byreference.

In the preferred embodiment, the six chemical treatment tests areperformed as follows.

The first test is an analysis of total serum protein (SP) and theremaining five tests are each used in the detection of a differentprotein. This is conventional in an IFE process.

The six tests are usually a total serum protein test [designated SP]followed by tests for the presence or absence of the monoclonalimmunoglobulins IgG, IgA, IgM, Kappa and Lambda [designated G, A, M, Kand L, respectively].

For the serum protein test, it is preferred that the fluid retainingsubstance be carrageenan. More specifically, the preferred serum proteinfixative is 10% acetic acid, 5% sulfosalicylic acid and 1% tannic acid.In the preferred method, this serum protein fixative (10% acetic acid,5% sulfosalicylic acid, 1% tannic acid) is mixed with 2% carrageenan andthen, the entire solution is diluted by one half. Therefore, in thefinal solution for the reservoir 616, approximately 1% carrageenan ispreferred.

The remaining five tests (tests number 2-6), use antisera. Each antisera[tests 2-6, G, A, M, K, and L] is mixed with a 2% low melting pointagarose so that the final concentration of the solution is 7.5milligrams per milliliter [mg/ml].

While carrageenan, a polysaccharide is preferred for the serum proteintest (as the fluid retaining substance or polymer), it is preferred thatthe antisera tests use agarose as the fluid retaining substance orpolymer with each respective antisera.

III. An Automatic System

The methods and techniques of the present invention can also beperformed automatically. FIG. 20 shows an example of an automaticimmuno-fixation electrophoresis system 200 which automates the methodsand techniques. The system has seven stations. The seven stations are:sample applicator station 301; electrophoresis station 302; antisera orchemical delivery station 303; first drying fan station 305; washstation 304; second drying fan station 306; and stain/destain station307.

The system is initiated when a carrier is inserted in the entrance 300.The carrier is a metal or plastic sheet or tray which is designed tomove between the stations. The mechanics which move the carrier can beconfigured a variety of ways, including a conveyor or other motorizeddelivery system 309. The timing of the movements is controlled with apreprogrammed microprocessor. For example, when a carrier is inserted inthe entrance and the system is initiated, the preprogrammedmicroprocessor instructs the motorized delivery system 309 to move thecarrier into the applicator station 301.

The applicator station 301 receives the carrier, selects a fluid samplewith a fluid applicator from a sample tray; deposits the sample on thesubstrate; and forwards the carrier to the electrophoresis station 302.Specifically, at the instruction of a preprogrammed microprocessor, amotorized device lowers the fluid applicator to retain the sample, movesthe fluid applicator to a position above the substrate, lowers the fluidapplicator to deposit the retained fluid on the substrate, and returnsthe fluid applicator to its home position.

Then the carrier is moved to the electrophoresis station 302. At theelectrophoresis station 302, the fluid sample is separated into itscomponent molecules with electrophoretic techniques.

Next, the carrier is moved to the antisera station 303. At the antiserastation 303, a substance or chemical delivery applicator is used toautomatically apply a substance or chemical to the separated molecules.Generally, these substances are designed to enhance the visibility ofcertain molecular structures. Similar to the sample applicator station301, the chemical delivery applicator is connected to a motorizedapparatus which automatically moves the applicator through the necessarysteps to apply the substance. Preferably, the chemicals are “pre-loaded”onto the chemical delivery applicator and therefore, no dunking step isnecessary.

After the substance or chemicals are applied, the carrier may be movedto the first wash station 304 and the first drying fan station 305.After the first drying station 305, the carrier may be moved to thestain/destain station 307, followed by the second drying station 306,and exit 308.

The foregoing description of the present invention has been presentedfor purposes of illustration and description. The description is notintended to limit the invention to the forms described. Variations andmodifications commensurate with the above teachings, and within theskill and knowledge of the relevant art, are part of the scope of thepresent invention.

What is claimed is:
 1. An apparatus for transferring a fluid from asupply to a substrate comprising: an applicator holder, and at least oneapplicator tip, connected to the holder, comprising a barrier, whereinthe applicator tip retains fluid below the barrier and the barriercontrols the amount of fluid deposited on the substrate, and furthercharacterized by at least one of the following (a) through (e); (a) thebarrier is selected from the group consisting of a physical barrier, atleast one aperture, and a rough surface; (b) the applicator tip has afirst portion and a second portion, the first and second portions aremade of a material selected from the group consisting of nylon andpolyester, and the second portion has a surface which is metalized toretain fluid; (c) the applicator tip has a first portion and a secondportion, the first portion is generally lyophobic; (d) the applicatortip has a first portion and a second portion, the second portion isgenerally lyophilic; (e) the applicator tip has a first portion and asecond portion, the second portion has a higher affinity to retain fluidby surface tension than the first portion.
 2. The apparatus of claim 1,wherein the barrier limits the amount of fluid retained.
 3. Theapparatus of claim 1, wherein the apparatus includes a plurality ofapplicator tips.
 4. An apparatus according to claim 1, and furthercomprising a base; an applicator guide, connected to the base, whereinthe applicator guide has at least one track; and an applicator rackalignable with the applicator guide comprising a pair of slots wherebythe pair of slots holds said applicator, the at least one track holdsthe pair of slots in a first position and a second position, and thesecond position is closer to the substrate than the first position. 5.The apparatus of claim 4, wherein the applicator guide has a first trackand a second track and wherein the first and second tracks are parallelto each other.
 6. The apparatus of claim 4, wherein the first track andthe second track each include at least one slide and wherein the pair ofslots moves from the first position to the second position by slidingdown the slides.
 7. The apparatus of claim 6, wherein the applicatorrack has at least two posts and the posts align with the slides.
 8. Theapparatus of claim 7, wherein the base and applicator guide are onepiece.
 9. The apparatus of claim 8, where in the base, applicator guide,and applicator rack are all one piece.
 10. The apparatus of claim 4,wherein the pair of slots is one of a first set of slots and whereby thefirst set of slots can hold several applicators simultaneously.
 11. Theapparatus of claim 10, wherein the applicator rack further comprises asecond set of slots aligned perpendicular to the first set of slots,whereby the first pair of slots can also hold several applicatorssimultaneously, and wherein the second set of slots are also held in afirst and second position.
 12. The apparatus of claim 11, wherein thesecond set of slots are held above the substrate in the first positionand closer to the substrate in the second position.
 13. The apparatus ofclaim 10, wherein the first set of slots holds a cartridge which holds aplurality of applicators.
 14. The apparatus of claim 10, wherein thebase, applicator guide, and applicator rack are components of anapplication station and wherein the application station is used inimmuno-fixation electrophoresis.
 15. The apparatus of claim 4, whereinthe pair of slots includes a first slot and a second slot and whereinthe first slot is larger than the second slot.
 16. The apparatus ofclaim 4, wherein the pair of slots holds a fluid applicator.
 17. Theapparatus of claim 4, wherein the pair of slots are moved from the firstposition to the second position electrically.
 18. The apparatus of claim4, wherein the pair of slots moves from the first position to the secondposition by moving in a vertical direction.
 19. The apparatus of claim4, wherein the substrate is held between the base and the applicatorguide.
 20. The apparatus of claim 4, wherein the pair of slots moves ina circular path from the first position to the second position.
 21. Theapparatus of claim 1, and further comprising: a reservoir, connected tothe applicator holder, comprising a fluid retaining substance; and fluiddispersed in the fluid retaining substance, wherein the fluid retainingsubstance delivers the dispersed fluid onto the substrate after contactis made between with the fluid retaining substance and the substrate.22. The apparatus of claim 21, wherein the reservoir is an elongatedwell.
 23. The apparatus of claim 21, wherein the reservoir istunnel-shaped and a portion of the fluid retaining substance is held inthe tunnel-shaped reservoir.
 24. The apparatus of claim 21, wherein thereservoir comprises an opening from which a portion of the fluidretaining substance protrudes and the protruding fluid retainingsubstance is brought into contact with the substrate.
 25. The apparatusof claim 24, wherein the opening opens away from the direction theholder is connected to the reservoir.
 26. The apparatus of claim 21,wherein the fluid retaining substance is poured into the reservoir. 27.The apparatus of claim 21, wherein the fluid retaining substance is castinto the reservoir.
 28. The apparatus of claim 21, wherein the fluidretaining substance adheres to the reservoir.
 29. The apparatus of claim21, wherein the fluid retaining substance traps the fluid.
 30. Theapparatus of claim 21, wherein the fluid retaining substance deliversthe fluid to the substrate by releasing the fluid upon contact with thesubstrate.
 31. The apparatus of claim 21, wherein the fluid retainingsubstance is a polymer.
 32. The apparatus of claim 31, wherein thepolymer is a gel.
 33. The apparatus of claim 32, wherein the gel isagarose.
 34. The apparatus of claim 31, wherein the polymer ispolysaccharide.
 35. The apparatus of claim 31, wherein the polymer iscarrageenan.
 36. The apparatus of claim 21, wherein the fluid is serumprotein.
 37. The apparatus of claim 21, wherein the fluid is antiserum.38. The apparatus of claim 21, wherein the holder comprises first andsecond guides.
 39. The apparatus of claim 38, wherein the first guideand second guide are of different thickness.
 40. The method of claim 39,further comprising the step of disposing the polymer after the polymerhas been contacted with the substrate.
 41. The apparatus of claim 21,further comprising a cartridge which connects the holder to a secondholder.
 42. The apparatus of claim 1, wherein the applicator holderfurther comprises a first guide and a second guide, wherein the firstguide is larger than the second guide.
 43. A method for transferring afluid from a supply to a substrate comprising: inserting an applicatorwith an applicator tip into a supply to retain fluid, wherein theapplicator tip has a barrier and a distal end; removing the applicatorfrom the supply, wherein the applicator tip retains fluid only betweenthe barrier and the distal end; moving the applicator tip with theretained fluid toward the substrate; and depositing the retained fluidon the substrate, and the applicator further characterized by at leastone of the following (a) through (e); (a) the barrier is selected fromthe group consisting of a physical barrier, at least one aperture, and arough surface; (b) the applicator tip has a first portion and a secondportion, the first and second portions are made of a material selectedfrom the group consisting of nylon and polyester, and the second portionhas a surface which is metalized to retain fluid; (c) the applicator tiphas a first portion and a second portion, the first portion is generallylyophobic; (d) the applicator tip has a first portion and a secondportion, the second portion is generally lyophilic; (e) the applicatortip has a first portion and a second portion, the second portion has ahigher affinity to retain fluid by surface tension than the firstportion.
 44. The method of claim 43, wherein the substrate includes agel onto which the retained fluid is transferred, the method furthercomprising: electrophoresing the deposited fluid to separate moleculeswithin, the deposited fluid.
 45. The method of claim 44, furthercomprising applying chemicals to the separated molecules to enhancevisibility of the separated molecules.
 46. The method of claim 44,wherein the fluid is a biological fluid.
 47. The method of claim 46,wherein the biological fluid is blood.
 48. The method of claim 44,wherein the gel is an agarose gel.
 49. The method of claim 44, whereinthe electrophoresis is an immuno-fixation electrophoresis.
 50. Themethod according to claim 43, and further comprising the steps of:placing a substrate between a base and an applicator guide; aligning anapplicator rack, including at least one applicator retaining fluid, withthe applicator guide; inserting at least one applicator retaining fluidinto the applicator rack; and wherein said step of depositing theretained fluid comprises lowering the applicator rack within theapplicator guide until the fluid retained on the at least one applicatoris deposited on the substrate; and raising the applicator rack away fromthe substrate.
 51. The method of claim 50, further comprising the stepsof: removing the applicator from the applicator rack; installing adispenser retaining a chemical in the applicator rack; and lowering theapplicator rack within the applicator guide until the chemical in thedispenser is deposited on the substrate.
 52. The method of claim 50,further comprising the step of: performing electrophoresis on thedeposited fluid.
 53. The method of claim 52, wherein the electrophoresisperformed is immuno-fixation electrophoresis.
 54. The method of claim43, further comprising: loading a polymer with the fluid; saidapplicator holder having a reservoir and the polymer; and contacting thesubstrate with the polymer whereby the loaded fluid is deposited on thesubstrate.
 55. The method of claim 54, wherein the step of loadingcomprises entrapping the fluid in the polymer.
 56. The method of claim54, wherein the step of loading comprises: mixing the polymer and thefluid; and pouring the polymer and the fluid into the reservoir.
 57. Themethod of claim 54, wherein at least a portion of the polymer is locatedinside the reservoir, the polymer and the fluid form a gel, and furthercomprising casting the gel in the reservoir.
 58. The method of claim 54,further comprising the step of removing the polymer